Neurogenic damage that causes dysarthria includes damage to the frontal lobe, posterior superior temporal gyrus, and brainstem. 1. Frontal lobe, the motor speech center is located in the posterior inferior frontal gyrus. Damage to this area can cause inability to speak, decreased word volume, and motor aphasia. 2. posterior superior temporal gyrus, damage to the posterior superior temporal gyrus can lead to sensory aphasia. The inability to understand other people’s speech, babbling, not being able to understand others, and not knowing what you are saying show up as sensory aphasia symptoms. Damage to the nerves in both areas can cause loss of speech. 3. Brainstem, damage to the brainstem nerves can cause motor disorders of the pharyngeal muscles, resulting in loss of speech or slurred speech, called dysarthria. If you have any of the above injuries that result in unclear speech, you should seek medical attention as soon as possible.